ObejectiveTo investigate the role of a novel chemically defined medium (CDM) in the regulation of dental papilla cells (DPCs) functional phenotype in vitro and periodontal bone regenerationin vivo.MethodsDPCs were isolated and cultured in conventional medium (CM) or CDM. The surface makers, and the proliferation, migration and osteogenic differentiation abilities of DPCs were evaluated.In vivo, the DPCs that mixed with collagen gel were implanted into the model rats in the defect of periodontal to repair the periodontal tissue. Regeneration of the tissues was examined by microcomputed tomography and histological observation.ResultsDPCs in the CM group and CDM group showed similar surface markers. Compared to the CM group, the CDM significantly enhanced the proliferation, colony-forming efficiency and migration of DPCsin vitro. In addition, real time PCR showed that the expression levels of osteogenesis-related genes,Runx2,AlpandOpn. were significantly enhanced in DPCs in the CDM group. DPCs cells treated with CDM also exhibited higher alkaline phosphatase activity and stronger ability of formation of mineralized nodulesin vitro. In vivo, DPCs from CDM group significantly enhanced the periodontal bone regeneration and the reconstruction of periodontal bone tissues in rat periodontal defect model.ConclusionCDM is a suitable medium to culture DPCs for periodontal bone regeneration. This research provided a substitute for basic research and set the stage for future clinical application of stem cell transplantation.